It all started when Chinese scientists fed rice and veggies to some mice. What they learned was kind of amazing: Genetic material from plant foods, called microRNA, altered the expression of some of the critters’ genes. Lab rats we are not, but these results, along with other research that found plant microRNA in human blood samples, suggest that microRNA “may block genes that are associated with cancer,” says Linda Birnbaum, Ph.D., director of the National Institute of Environmental Health Sciences. This knowledge could be crucial to preventing tumors from developing, because most cancers begin when genes switch on or off inappropriately, causing cells to grow out of control. First, though, more research needs to be done to see how plant microRNA works in the human body.

What to do: Eat the good stuff. Lots of it—at least 2 1/2 cups of vegetables and 1 1/2 cups of fruit every day. You’ll know you’re on the right track if half of what’s on your plate at meals is produce. Be sure to mix things up: Different fruit and vegetables contain different microRNA and cancer-fighting antioxidants.

Your perk: Fewer munchies. Produce is full of fiber, which helps keep you full longer, so you eat less.

Good sugar levels may drop your risk.

Got your sweet tooth under control? Great! Type 2 diabetes may raise your chances of developing cancer, research finds. One possible culprit: insulin. When people become insulin-resistant—often because of weight gain—their body produces more of the hormone to compensate. “Certain body tissues, including those in the breast and colon, have insulin receptors. It’s likely that high insulin levels speed the growth of those tissues, which leads to damage that can result in cancer,” explains Lewis Cantley, Ph.D., a biochemist at Beth Israel Deaconess Medical Center.

What to do: Keep that blood sugar in check. If you’re not already eating whole-wheat everything, now is the time to start. Your body processes refined carbs quickly, causing your blood sugar to spike and insulin levels to go up, Cantley says. And beware of added sugars, such as honey, agave nectar and dextrose, which often sneak into packaged foods.

OK, we know we just said to lay off the sugar. But there’s an exception: The polyphenols in cocoa beans may prevent cellular changes that cause cancerous cells to grow, a study in Molecular Nutrition & Food Research reports. The research was done on animals, but the study’s authors speculate that the benefits could apply to humans, too.

What to do: Pick your chocolate wisely. To get the most polyphenols and the least sugar, look for dark chocolate with a minimum 70 percent cocoa and stick to a small square (about 1 ounce) a day. More is not better.

Your perk: Skinny jeans. Adults who regularly eat chocolate are up to 7 pounds slimmer than those who don’t eat the treat, research finds.

Exercise more: It's great for your breasts.

This summer brought happy news for active girls. Those who get moving for 10 to 19 hours a week slash their odds of cancer later in life by one third. This particular study in Cancer looked at breast cancer risk, but physical activity may also protect us from colon and lung cancer, in part by altering levels of insulin and other hormones that can drive cancer development.

What to do: Ten to 19 hours in seven days may seem like a ton, but it’s totally doable. The new research found that intensity doesn’t matter, which means that activities such as walking the dog and cleaning count, says lead researcher Lauren McCullough of the University of North Carolina at Chapel Hill.

Your perk: An easier cycle. If PMS makes you moody, there’s evidence that breaking a sweat could help lift the black cloud.

Folate isn't only for pregnant ladies.

Women with high levels of folate in their diet have a 40 percent lower risk for premenopausal breast cancer compared with women who consume little of the B vitamin, researchers at Vanderbilt University and the Shanghai Cancer Institute discovered. Your cells use folate to make and repair DNA, and damaged genes can spur cancer growth. Also cool: Getting enough of the vitamin may offset the risks of moderate drinking. Alcohol blocks the absorption of folate and has been linked to an increased risk for breast cancer.

What to do: Aim for 400 micrograms of folate daily by loading up on foods such as leafy greens and citrus fruit. No supplement needed.

Your perk: A happier mood. Folate stimulates production of the feel-good chemical serotonin. People with low levels are more likely to be depressed.

Dim the lights. You just might fight cancer.

Being exposed to ordinary room light in the evening decreases levels of the hormone melatonin, a study in The Journal of Clinical Endocrinology & Metabolism shows. Melatonin not only helps bring on sleep, but it may also regulate estrogen, a key hormone associated with breast cancer. This study could in part explain what scientists have long suspected: Exposure to artificial light after sundown may increase our cancer risk, says Richard Stevens, Ph.D., a cancer epidemiologist at the University of Connecticut Health Center. Another hint: Women on the night shift get more breast cancer than nine-to-fivers.

What to do: Switch to lamps with low-intensity incandescent bulbs (no fluorescent lights!) about two hours before bed. Stevens also recommends installing a dim red bulb in the bathroom. That way, you won’t mess with your melatonin when you’ve got to pee at 3 a.m.

Mindfulness meditation, based in Buddhist tradition, may help you quit cigarettes by decreasing activity in a part of the brain that’s linked to cravings, a study in Social Cognitive and Affective Neuroscience reports. And meditation could help you break other habits that may be putting you at risk for cancer, like binge drinking and eating fatty comfort foods, says Kevin Patterson, M.D., medical director for clinical behavioral medicine at Hillman Cancer Center in Pittsburgh. But wait—there’s more. New research suggests that mindfulness meditation may increase telomerase, an enzyme that’s vital to normal cell division, in the immune system. It’s too early to know if this can reduce your cancer risk, but it’s pretty clear that meditation has some nice benefits.

What to do: Start meditating! Find a quiet place, and set a timer for two minutes, says Marsha Lucas, Ph.D., a neuropsychologist in Washington, D.C. Close your eyes, and pay attention to your breath; continue until the timer sounds. Try adding a minute each day; work up to 10 to 20 minutes.

Your perk: Better sex. Mindfulness meditation could enhance the insula, a part of the brain linked to awareness. Regular meditation may make it easier to get aroused and even improve orgasms. What’s not to love?